The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands.
Adenoid cystic carcinoma is a rare type of cancer that can exist in many different body sites. This tumor most often occurs in the salivary glands, but it can also be found in many anatomic sites, including the breast, lacrimal gland, lung, brain, bartholin gland, trachea, and the paranasal sinuses.
Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of epithelial (ductal) cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which refers to its dual origin from epithelial and myoepithelial elements as opposed to its pleomorphic appearance.
Benign lymphoepithelial lesion or Mikulicz' disease is a type of benign enlargement of the parotid and/or lacrimal glands. This pathologic state is sometimes, but not always, associated with Sjögren's syndrome.
Mucoepidermoid carcinoma (MEC) is the most common type of minor salivary gland malignancy in adults. Mucoepidermoid carcinoma can also be found in other organs, such as bronchi, lacrimal sac, and thyroid gland.
Sialadenitis (sialoadenitis) is inflammation of salivary glands, usually the major ones, the most common being the parotid gland, followed by submandibular and sublingual glands. It should not be confused with sialadenosis (sialosis) which is a non-inflammatory enlargement of the major salivary glands.
Salivary gland tumours, also known as mucous gland adenomas or neoplasms, are tumours that form in the tissues of salivary glands. The salivary glands are classified as major or minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor salivary glands consist of 800 to 1000 small mucus-secreting glands located throughout the lining of the oral cavity. Patients with these types of tumours may be asymptomatic.
Odontogenic cyst are a group of jaw cysts that are formed from tissues involved in odontogenesis. Odontogenic cysts are closed sacs, and have a distinct membrane derived from rests of odontogenic epithelium. It may contain air, fluids, or semi-solid material. Intra-bony cysts are most common in the jaws, because the mandible and maxilla are the only bones with epithelial components. That odontogenic epithelium is critical in normal tooth development. However, epithelial rests may be the origin for the cyst lining later. Not all oral cysts are odontogenic cyst. For example, mucous cyst of the oral mucosa and nasolabial duct cyst are not of odontogenic origin.
In addition, there are several conditions with so-called (radiographic) 'pseudocystic appearance' in jaws; ranging from anatomic variants such as Stafne static bone cyst, to the aggressive aneurysmal bone cyst.
Salivary duct carcinoma (SDC) is a rare type of aggressive cancer that arises from the salivary glands. It is predominantly seen in men and, generally, has a poor prognosis. Other high grade carcinomas can mimic SDC. About 40-60% of SDC arise in pleomorphic adenomas. Most, if not all, SDCs express androgen receptor by immunohistochemistry. Therapeutically relevant genetic alterations include ERBB2/Her2 amplification, PIK3CA and/or HRAS mutations.
Collagenous spherulosis, or simple spherulosis, is a benign finding in breast pathology. It is almost always an incidental finding, though it is occasionally associated with calcifications, which may lead to a biopsy.
The uterus-like mass (ULM) is a tumorlike anatomical entity originally described in the ovary in 1981 and thereafter reported in several locations of the pelvis and abdominal cavity including broad ligament, greater omentum, cervix, small intestine, mesentery and conus medullaris. Basically, it is represented by a miniature uterus comprising a smooth muscle wall lined by endometrium thus outlining a uterus anatomical structure. Some of the reported cases have been associated to urinary tract and internal genitalia malformations whereas others appeared as a solitary finding. The term endomyometriosis has also been applied to this lesion.
Myoepithelioma of the head and neck, also myoepithelioma, is a salivary gland tumour of the head and neck that is usually benign. When malignant, which is exceedingly rare, they are known as malignant myoepithelioma or Myoepithelial carcinoma, and they account for 1% of the salivary tumors with poor prognosis.
Epithelial-myoepithelial carcinoma (EMCa) is a rare malignant tumour that typically arises in a salivary gland and consists of both an epithelial and myoepithelial component. They are predominantly found in the parotid gland and represent approximately 1% of salivary gland tumours.
A sialoblastoma is a low-grade salivary gland neoplasm that recapitulates primitive salivary gland anlage. It has previously been referred to as congenital basal cell adenoma, embryoma, or basaloid adenocarcinoma. It is an extremely rare tumor, with less than 100 cases reported worldwide.
Carcinoma ex pleomorphic adenoma is a type of cancer typically found in the parotid gland. It arises from the benign tumour pleomorphic adenoma.
Salivary gland diseases (SGD) are multiple and varied in cause.
Chronic sclerosing sialadenitis is a chronic (long-lasting) inflammatory condition affecting the salivary gland. Relatively rare in occurrence, this condition is benign, but presents as hard, indurated and enlarged masses that are clinically indistinguishable from salivary gland neoplasms or tumors. It is now regarded as a manifestation of IgG4-related disease.
Microglandular hyperplasia (MGH) of the cervix is an epithelial benign abnormality (lesion) associated with gland proliferation. It can terminate in mature squamous metaplasia, and it is suspected reserve cells are involved in this process, perhaps in the form of reserve cell hyperplasia with glandular differentiation.
Mammary analogue secretory carcinoma (MASC), also termed MASCSG, is a salivary gland neoplasm. It is a secretory carcinoma which shares the microscopic pathologic features with other types of secretory carcinomas including mammary secretory carcinoma, secretory carcinoma of the skin, and salivary gland–type carcinoma of the thyroid. MASCSG was first described by Skálová et al. in 2010. The authors of this report found a chromosome translocation in certain salivary gland tumors, i.e. a (12;15)(p13;q25) fusion gene mutation. The other secretory carcinoma types carry this fusion gene.
Secretory carcinoma was once used exclusively as a term for rare, slowly growing breast tumors without reference to their location in the breast. It is now termed mammary secretory carcinoma because secretory carcinoma has sometimes been used to name tumors which develop in non-breast tissues but have the microscopic appearance of, and a critical gene abnormality found in, mammary secretory carcinoma. This genetic abnormality is a balanced genetic translocation that forms a ETV6-NTRK3 fusion gene which appears involved in promoting the development and/or progression of all these tumors. The formerly termed secretory carcinomas include:
